This invention relates to an apparatus that is used as a small animal litter box, specifically, a litter box within which soiled granular litter material and animal faeces may be readily separated from the remaining unsoiled litter material for subsequent removal and disposal.
Owners and breeders of small animals such as cats which spend a majority of their time indoors, enjoy the convenience which comes from training their animals to utilise a litter box. The inconvenience of this training however, is the need to frequently clean the litter box by separating the resulting animal waste and soiled litter from the unsoiled reusable litter material, removing the waste material from the litter box and depositing the waste in a disposal receptacle.
Litter boxes for pets such as cats and similar small animals abound in the prior art and have addressed the problem of separating animal faecal material and soiled litter from the balance of clean, reusable granular litter material in a manner which is similar to the present invention. The preferred manner of separating animal faecal material and soiled litter from the balance of clean, reusable granular litter material, being the employment of a pair of identical receptacles for receiving litter material intended for use by a pet and a screen which is used to filter the litter.
The receptacles are generally rectangular in shape and have a outwardly projecting flange surrounding an open face. The screen is sized so as to completely cover the receptacle opening and has formed upon opposed edges upper and lower receivers which receive opposed pairs of outwardly projecting perimeter flanges on the receptacle.
During the operation of the litter box, a first receptacle only of the pair of receptacles is used to retain litter material. When such litter material becomes soiled the screen is placed over the first receptacle. The second receptacle, which is empty, is inverted into opposed open facing relationship with the first receptacle, to act as a cover and is placed into engagement with the edges of the screen.
Soiled litter and animal faecal material are now separated from the balance of clean, reusable granular litter material by inverting the assembled receptacles and screen. The granular litter material passes through the screen by the force of gravity, which can be assisted by mild agitation of the inverted receptacles. The soiled litter and animal waste material is retained on the screen for subsequent disposal. The upper receptacle along with the attached screen is separated from the lower receptacle and inverted allowing the separated material to fall from the screen into the upper receptacle for subsequent discharge into a disposal container.
The applicant is aware of U.S. Pat. Nos. 4,325,822, 5,012,765 and 5,598,810 wherein the above noted features are disclosed and U.S. Pat. No. 5,806,461 which contains an animal access door and a paw cleaning walkway.
The present invention is a litter box for use by small household pets such as cats. The device may have its parts manufactured from resilient material such as plastic or the like. Primarily the device comprises substantially identical, and interchangeable, first and second litter receiving receptacles and a screen.
The first litter receiving receptacle is filled with absorbent granular litter material into which excreta is deposited by the pet. When cleaning of the litter box is required, which advantageously entails separating the excreta and clumped soiled litter from clean, reusable litter, the screen is fitted over the first litter receiving receptacle. The second litter receiving receptacle is then inverted and placed on top of the screen so that the first and second litter receiving receptacles are positioned in an opposed facing relationship. By rotating the assembled litter box so that the first litter receiving receptacle is uppermost, i.e. so as to invert the first litter receiving receptacle and with mild agitation, the clean granular litter will filter through the screen leaving excreta and clumps of soiled litter on the screen where such material may be easily be disposed by re-inverting of the fist receptacle and screen, and depositing of the excreta and clumps of soiled litter through a gated aperture in one side or end of the first receptacle. Advantageously the internal surface of the first receptacle adjacent the gated aperture is shaped to funnel the excreta and clumps towards and through the aperture so as to avoid the excreta and clumps becoming lodged in the corners of the first receptacle.
Thus, the litter box of the present invention includes first and second litter receiving receptacles, each having a base and a perimeter wall co-extensive with, and surrounding, the base. The perimeter wall defines a litter receiving chamber in each receptacle. An outwardly projecting flange member is integrally formed with the perimeter wall surrounding the litter receiving chamber at an edge of the walls remote from the base of the litter receiving receptacle. The first receptacle has granular litter material placed therein and the second receptacle is placed inverted over the first receptacle so as to place the respective receiving chambers in opposed facing relationship.
In one embodiment the gated aperture is releasably closed by a flap integrally formed in a portion of said perimeter wall, the flap flexibly hinged near to the base. The flap is held closed by a latch or other releasable closure means. A wedge-shaped convergence or funnel is formed between the perimeter wall and the base of each litter receiving receptacle, in proximity to the flap. The convergence or funnel diverges, that is, increases in width from a point remote from the flap to an intersection adjacent to the flap for funneling excreta toward the flap.
A deflector lip member projects inwardly integral with said perimeter wall surrounding said litter receiving chamber and extends co-planar with said outwardly projecting flange member. A screen is adapted to completely cover said receiving chamber and said outwardly projecting flange member of said litter receiving receptacles. The screen has handles, integrally formed with said screen, located medially on each of opposed ends of said screen, generally on ends opposite to the end containing said flap. Upper and lower wing portions of said handle extend at right angles to the respective faces of said screen.
The screen and containers are a snap together fitting rather than a fitting that required receivers or channels on the screen to be slid over the outer perimeter flange on the containers. The wings contain inwardly facing buttons which permit said outwardly projecting flange member of said litter receiving receptacles, when placed within the confines of said upper and lower wings of said handles and when forced vertically toward said screen, to push against said buttons to thereby force said wing portions slightly outwardly permitting said outwardly projecting flange member to be snapped into place between said buttons and said screen thereby retaining said receptacles in close proximity over said screen.
A review of the prior art fails to disclose, and it is an object of the present invention to provide an inwardly projecting perimeter lip which functions as a litter deflector around the open face of each litter receptacle, an opening or aperture in the end wall of each litter receptacle which is normally kept closed off by a hinged flap, gate or door, and converging funnel interior side walls in each receptacle adjacent to the end wall opening or aperture. The litter deflector returns litter which is scraped upwards along the sides of the litter receptacle by, for example, a cat during the act of burying the excreta, to thereby substantially reduce the associated spillage. The opening in the end wall permits the user to empty the waste material out of the container, after tumbling the assembled screen and litter container components, without first having to disassemble the screen from the waste receiving container. Further, the risk of feline or waste litter falling from the screen during disposal is eliminated. The converging funnel interior side walls adjacent to the end wall opening eliminate angular corners and serve to funnel waste material and soiled litter cleanly toward and through the end wall opening.
In summary, the litter box of the present invention includes first and second mirror-image litter containers mountable on either side of a litter screen. Each container has an opening into a corresponding litter receiving cavity. The litter screen is removably mountable by a snap-on fit onto each of the first and second containers. The screen is sandwiched between the first and second containers when the first and second containers are mounted onto the screen in opposed facing array so that the openings of the containers are disposed against the screen. The screen completely covers the openings when so mounted.
Each container has an aperture in a wall thereof. Each aperture is releasably closable by a corresponding manually operable door. Each cavity is shaped to funnel waste screened by the screen from the litter into the aperture upon manual inclination of cavity towards the aperture by a user.
In one aspect of the present invention the first and second containers are flat-bottomed containers having planar base surfaces. The openings of the containers are oppositely disposed on the containers to the base surfaces. Side walls extend contiguously around and between the base surfaces and the openings, and each aperture is formed in the side walls of each container. The side walls and base surfaces define the cavities. The side walls and base surfaces are formed as funnels adjacent each aperture in each container.
In one preferred embodiment, not intended to be limiting, the manually operable gate is a hinged flap releasably securable in a closed position by a closure means so as to seal each aperture. Each funnel may be wedge-shaped ramps extending along an intersection between the side walls and the base surface. Advantageously, the base surfaces and the openings on each container are substantially parallel. Further, each container may be substantially a parallelepiped, for example, rectangular.
In a second aspect, flexible releasable latches are mounted on the screen for releasably mounting the screen in the sandwich snap-on fit onto each container. The latches may be resilient oppositely disposed pairs of cantilevered members, cantilevered substantially orthogonally outwardly of opposite side edges of the screen for frictionally engaging corresponding edges of side walls of the first and second containers. The latches may frictionally engage the edges of the side walls by mating the edges between the screen and latching protrusions such as bumps on the cantilevered members and the screen. The cantilevered members may be described as wings, and may be mounted to the screen medially along each side edge of the screen.
In yet a further aspect, the openings of the containers are defined by a circumferential lip on each container extending around each opening. The circumferential lip extends radially inwardly into the opening so as to extend cantilevered over the cavity for deflecting litter thrown within the cavity from being thrown out through the opening.